Ladda Kaewklapanyacharoen2011-02-162011-02-162011-02-022011-02-02Bulletin of the Department of Medical Sciences - วารสารกรมวิทยาศาสตร์การแพทย์; Vol.50 No.1 January - March 2008; 1-13http://imsear.searo.who.int/handle/123456789/130477ABSTRACT  m g/kg and limit of quantitation (LOQ) was 0.5 mg/kg. The linear working range for brombuterol, clenbuterol,ractopamine and salbutamol was 0.5-10.0 mg/kg with the correlation coefficient 0.9989, 0.9986, 0.9974and 0.9988, respectively. Accuracy of the method was shown by mean % recovery of spiking standard tosample matrix at 5 different levels within linear working range were 61.7-84.3, 69.1-100.7, 64.8-104.4and 88.1-104.8 for brombuterol, clenbuterol, ractopamine and salbutamol, respectively. Precision wasshown by relative standard deviation percentage (%RSD) were 8.7-14.9, 8.6-12.6, 7.8-13.9 and3.6-11.6 for brombuterol, clenbuterol, ractopamine and sabutamol, respectively. Validation data proved thatthis method could be used for determining brombuterol, clenbuterol, ractopamine and salbutamol in animaltissues for food quality control by law. This method was used to analysed 30 samples of pork that hadbeen analysed by ELISA method. It showed that both methods gave the equivalent results for 90% ofthe total samples.Key word : brombuterol, clenbuterol, ractopamine, salbutamol, animal tissue, LC-MS/MSA simultaneous determination of brombuterol, clenbuterol, ractopamine and salbutamolresidues in animal tissue using LC-MS/MS was validated. The meat sample was digested by dilute hydrochloricacid, extracted and cleaned up on solid phase extraction mixed mode cation exchange/reverse phase(MCX mode), followed by determination of residues by liquid chromatograph tandem mass spectometryusing electrospray ionization in positive ion mode. The result showed that the limit of detection (LOD) was 0.3en-USBulletin of the Department of Medical Sciences - วารสารกรมวิทยาศาสตร์การแพทย์Original Articles